Abstract

Social withdrawal is a robust childhood risk factor for later schizophrenia. The aims of this paper were to assess the evidence for childhood social withdrawal among adults with schizophrenia and, comparatively, in children aged 9–14 years who are putatively at-risk of developing schizophrenia. We conducted a meta-analysis, including cohort and case-control studies reporting social withdrawal measured by the Child Behavior Checklist (CBCL) in adults with schizophrenia vs. controls. Further, an experimental study compared CBCL withdrawal scores from typically-developing children with scores from two groups of putatively at-risk children: (i) children displaying a triad of replicated antecedents for schizophrenia, and (ii) children with at least one first- or second-degree relative with schizophrenia or schizoaffective disorder. Six studies met inclusion criteria for the meta-analysis (N = 3828), which demonstrated a large effect of increased childhood social withdrawal in adults with schizophrenia (standardized mean difference [SMD] score = 1.035, 95% CI = 0.304–1.766, p = 0.006), with no indication of publication bias, but considerable heterogeneity (I2 = 91%). Results from the experimental study also indicated a large effect of increased social withdrawal in children displaying the antecedent triad (SMD = 0.743, p = 0.001), and a weaker effect in children with a family history of schizophrenia (SMD = 0.442, p = 0.051). Childhood social withdrawal may constitute a vulnerability marker for schizophrenia in the presence of other antecedents and/or genetic risk factors for schizophrenia.